Is there a relationship between coolant temperature and open/closed loop status?
Yes
Open loop occours when engine is cold
The ecu ignores lambda readings and runs a base program to get engine warmed up, the information is there but it goes nowhere so the loops open
When on wide open throttle - again it ignore this sensor as well, alot of cars do as your wanting full power not low emisions....
Closed loop is when criteria is met about the engine
When warmed up the ecu wants to see the fueling
If the lambda say its too rich - ecu cuts injection time and recieves the new signal from sensor
Typically it now says lean condition and tue injection time opens up
This is going on soo many times its called closed loop
Earthing the sensor straight out will often just confuse the sensors readings as i believe the ecu is actually the negative switch on it
Most lambdas have 4 wires
Usually 2 white or 2 grey are the heater element - not polarity sensitive as its just a coil of wire
Then there are 2 more wires for the oxygen reading bit of the sensor - colours differ so a diagram may be needed to identify the sensor circuit
This is a polarity sensitive circuit as there is often a full time power and ecu controlled negative switching
Whats the fault code you getting?
What makes you say lambda at fault?
Ziggy
